Since 1989, H.S.H. Prince Hans-Adam II has reigned in Liechtenstein. Comprising 62 square miles nestled between Austria and Switzerland with a population of about 35,000, Liechtenstein is one of the world's smallest nations—but has the highest per capita GDP in the world. The head of a family that traces its history back more than 900 years, to the beginning of the second millennium, Prince Hans-Adam is the author of a new book, The State in the Third Millennium.